/****************************************************************************
**
** This file is part of the KD Chart library.
**
** SPDX-FileCopyrightText: 2001 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
**
** SPDX-License-Identifier: MIT
**
****************************************************************************/

#include "kdganttgraphicsscene.h"
#include "kdganttabstractrowcontroller.h"
#include "kdganttconstraint.h"
#include "kdganttconstraintgraphicsitem.h"
#include "kdganttdatetimegrid.h"
#include "kdganttgraphicsitem.h"
#include "kdganttgraphicsscene_p.h"
#include "kdganttitemdelegate.h"
#include "kdganttsummaryhandlingproxymodel.h"

#include <QApplication>
#include <QGraphicsSceneHelpEvent>
#include <QPainter>
#include <QPrinter>
#include <QSet>
#include <QTextDocument>
#include <QToolTip>

#include <QDebug>

#include <algorithm>
#include <cassert>
#include <functional>

// defines HAVE_PRINTER if support for printing should be included
#ifdef _WIN32_WCE
// There is no printer support under wince even if QT_NO_PRINTER is not set
#else
#ifndef QT_NO_PRINTER
#define HAVE_PRINTER
#endif
#endif

/*!\class KDGantt::GraphicsScene
 * \internal
 */

using namespace KDGantt;

GraphicsScene::Private::Private(GraphicsScene *_q)
    : q(_q)
    , dragSource(nullptr)
    , itemDelegate(new ItemDelegate(_q))
    , rowController(nullptr)
    , grid(&default_grid)
    , readOnly(false)
    , isPrinting(false)
    , drawColumnLabels(true)
    , labelsWidth(0.0)
    , summaryHandlingModel(new SummaryHandlingProxyModel(_q))
    , selectionModel(nullptr)
{
    default_grid.setStartDateTime(QDateTime::currentDateTime().addDays(-1));
}

void GraphicsScene::Private::resetConstraintItems()
{
    q->clearConstraintItems();
    if (constraintModel.isNull())
        return;
    const QList<Constraint> clst = constraintModel->constraints();
    for (const Constraint &c : clst) {
        createConstraintItem(c);
    }
    q->updateItems();
}

void GraphicsScene::Private::createConstraintItem(const Constraint &c)
{
    GraphicsItem *sitem = q->findItem(summaryHandlingModel->mapFromSource(c.startIndex()));
    GraphicsItem *eitem = q->findItem(summaryHandlingModel->mapFromSource(c.endIndex()));

    if (sitem && eitem) {
        auto *citem = new ConstraintGraphicsItem(c);
        sitem->addStartConstraint(citem);
        eitem->addEndConstraint(citem);
        q->addItem(citem);
    }

    // q->insertConstraintItem( c, citem );
}

// Delete the constraint item, and clean up pointers in the start- and end item
void GraphicsScene::Private::deleteConstraintItem(ConstraintGraphicsItem *citem)
{
    // qDebug()<<"GraphicsScene::Private::deleteConstraintItem citem="<<citem;
    if (citem == nullptr) {
        return;
    }
    Constraint c = citem->constraint();
    GraphicsItem *item = items.value(summaryHandlingModel->mapFromSource(c.startIndex()), 0);
    if (item) {
        item->removeStartConstraint(citem);
    }
    item = items.value(summaryHandlingModel->mapFromSource(c.endIndex()), 0);
    if (item) {
        item->removeEndConstraint(citem);
    }
    delete citem;
}

void GraphicsScene::Private::deleteConstraintItem(const Constraint &c)
{
    deleteConstraintItem(findConstraintItem(c));
}

ConstraintGraphicsItem *GraphicsScene::Private::findConstraintItem(const Constraint &c) const
{
    GraphicsItem *item = items.value(summaryHandlingModel->mapFromSource(c.startIndex()), 0);
    if (item) {
        const QList<ConstraintGraphicsItem *> clst = item->startConstraints();
        QList<ConstraintGraphicsItem *>::const_iterator it = clst.begin();
        for (; it != clst.end(); ++it) {
            if (c.compareIndexes((*it)->constraint()))
                break;
        }
        if (it != clst.end()) {
            return *it;
        }
    }
    item = items.value(summaryHandlingModel->mapFromSource(c.endIndex()), 0);
    if (item) {
        const QList<ConstraintGraphicsItem *> clst = item->endConstraints();
        QList<ConstraintGraphicsItem *>::const_iterator it = clst.begin();
        for (; it != clst.end(); ++it) {
            if (c.compareIndexes((*it)->constraint()))
                break;
        }
        if (it != clst.end()) {
            return *it;
        }
    }
    return nullptr;
}

GraphicsScene::GraphicsScene(QObject *parent)
    : QGraphicsScene(parent)
    , _d(new Private(this))
{
    init();
}

GraphicsScene::~GraphicsScene()
{
    clearConstraintItems();
    qDeleteAll(items());
    delete _d;
}

#define d d_func()

void GraphicsScene::init()
{
    setItemIndexMethod(QGraphicsScene::NoIndex);
    setConstraintModel(new ConstraintModel(this));
    connect(d->grid, &AbstractGrid::gridChanged, this, &GraphicsScene::slotGridChanged);
}

/* NOTE: The delegate should really be a property
 * of the view, but that doesn't really fit at
 * this time
 */
void GraphicsScene::setItemDelegate(ItemDelegate *delegate)
{
    if (!d->itemDelegate.isNull() && d->itemDelegate->parent() == this)
        delete d->itemDelegate;
    d->itemDelegate = delegate;
    update();
}

ItemDelegate *GraphicsScene::itemDelegate() const
{
    return d->itemDelegate;
}

QAbstractItemModel *GraphicsScene::model() const
{
    assert(!d->summaryHandlingModel.isNull());
    return d->summaryHandlingModel->sourceModel();
}

void GraphicsScene::setModel(QAbstractItemModel *model)
{
    assert(!d->summaryHandlingModel.isNull());
    d->summaryHandlingModel->setSourceModel(model);
    d->grid->setModel(d->summaryHandlingModel);
    setSelectionModel(new QItemSelectionModel(model, this));
}

QAbstractProxyModel *GraphicsScene::summaryHandlingModel() const
{
    return d->summaryHandlingModel;
}

void GraphicsScene::setSummaryHandlingModel(QAbstractProxyModel *proxyModel)
{
    proxyModel->setSourceModel(model());
    d->summaryHandlingModel = proxyModel;
}

void GraphicsScene::setRootIndex(const QModelIndex &idx)
{
    d->grid->setRootIndex(idx);
}

QModelIndex GraphicsScene::rootIndex() const
{
    return d->grid->rootIndex();
}

ConstraintModel *GraphicsScene::constraintModel() const
{
    return d->constraintModel;
}

void GraphicsScene::setConstraintModel(ConstraintModel *cm)
{
    if (!d->constraintModel.isNull()) {
        d->constraintModel->disconnect(this);
    }
    d->constraintModel = cm;

    connect(cm, &ConstraintModel::constraintAdded,
            this, &GraphicsScene::slotConstraintAdded);
    connect(cm, &ConstraintModel::constraintRemoved,
            this, &GraphicsScene::slotConstraintRemoved);
    d->resetConstraintItems();
}

void GraphicsScene::setSelectionModel(QItemSelectionModel *smodel)
{
    d->selectionModel = smodel;
    // TODO: update selection from model and connect signals
}

QItemSelectionModel *GraphicsScene::selectionModel() const
{
    return d->selectionModel;
}

void GraphicsScene::setRowController(AbstractRowController *rc)
{
    d->rowController = rc;
}

AbstractRowController *GraphicsScene::rowController() const
{
    return d->rowController;
}

void GraphicsScene::setGrid(AbstractGrid *grid)
{
    QAbstractItemModel *model = nullptr;
    if (grid == nullptr)
        grid = &d->default_grid;
    if (d->grid) {
        d->grid->disconnect(this);
        model = d->grid->model();
    }
    d->grid = grid;
    connect(d->grid, &AbstractGrid::gridChanged, this, &GraphicsScene::slotGridChanged);
    d->grid->setModel(model);
    slotGridChanged();
}

AbstractGrid *GraphicsScene::grid() const
{
    return d->grid;
}

void GraphicsScene::setReadOnly(bool ro)
{
    d->readOnly = ro;
}

bool GraphicsScene::isReadOnly() const
{
    return d->readOnly;
}

/* Returns the index with column=0 from the
 * same row as idx and with the same parent.
 * This is used to traverse the tree-structure
 * of the model
 */
QModelIndex GraphicsScene::mainIndex(const QModelIndex &idx)
{
#if 0
    if ( idx.isValid() ) {
        return idx.model()->index( idx.row(), 0,idx.parent() );
    } else {
        return QModelIndex();
    }
#else
    return idx;
#endif
}

/*! Returns the index pointing to the last column
 * in the same row as idx. This can be thought of
 * as in "inverse" of mainIndex()
 */
QModelIndex GraphicsScene::dataIndex(const QModelIndex &idx)
{
#if 0
    if ( idx.isValid() ) {
        const QAbstractItemModel* model = idx.model();
        return model->index( idx.row(), model->columnCount( idx.parent() )-1,idx.parent() );
    } else {
        return QModelIndex();
    }
#else
    return idx;
#endif
}

/*! Creates a new item of type type.
 * TODO: If the user should be allowed to override
 * this in any way, it needs to be in View!
 */
GraphicsItem *GraphicsScene::createItem(ItemType type) const
{
#if 0
    switch ( type ) {
    case TypeEvent:   return 0;
    case TypeTask:    return new TaskItem;
    case TypeSummary: return new SummaryItem;
    default:          return 0;
    }
#endif
    // qDebug() << "GraphicsScene::createItem("<<type<<")";
    Q_UNUSED(type);
    return new GraphicsItem;
}

void GraphicsScene::Private::recursiveUpdateMultiItem(const Span &span, const QModelIndex &idx)
{
    // qDebug() << "recursiveUpdateMultiItem("<<span<<idx<<")";
    GraphicsItem *item = q->findItem(idx);
    const int itemtype = summaryHandlingModel->data(idx, ItemTypeRole).toInt();
    if (!item) {
        item = q->createItem(static_cast<ItemType>(itemtype));
        item->setIndex(idx);
        q->insertItem(idx, item);
    }
    item->updateItem(span, idx);
    QModelIndex child;
    int cr = 0;
    while ((child = idx.model()->index(cr, 0, idx)).isValid()) {
        recursiveUpdateMultiItem(span, child);
        ++cr;
    }
}

void GraphicsScene::updateRow(const QModelIndex &rowidx)
{
    // qDebug() << "GraphicsScene::updateRow("<<rowidx<<")" << rowidx.data( Qt::DisplayRole );
    if (!rowidx.isValid())
        return;
#if !defined(NDEBUG)
    const QAbstractItemModel *model = rowidx.model(); // why const?
#endif
    assert(model);
    assert(rowController());
    assert(model == summaryHandlingModel());

    const QModelIndex sidx = summaryHandlingModel()->mapToSource(rowidx);
    Span rg = rowController()->rowGeometry(sidx);
    for (QModelIndex treewalkidx = sidx; treewalkidx.isValid(); treewalkidx = treewalkidx.parent()) {
        if (treewalkidx.data(ItemTypeRole).toInt() == TypeMulti
            && !rowController()->isRowExpanded(treewalkidx)) {
            rg = rowController()->rowGeometry(treewalkidx);
        }
    }

    bool blocked = blockSignals(true);
    for (int col = 0; col < summaryHandlingModel()->columnCount(rowidx.parent()); ++col) {
        const QModelIndex idx = summaryHandlingModel()->index(rowidx.row(), col, rowidx.parent());
        const QModelIndex sidx = summaryHandlingModel()->mapToSource(idx);
        const int itemtype = summaryHandlingModel()->data(idx, ItemTypeRole).toInt();
        const bool isExpanded = rowController()->isRowExpanded(sidx);
        if (itemtype == TypeNone) {
            removeItem(idx);
            continue;
        }
        if (itemtype == TypeMulti && !isExpanded) {
            d->recursiveUpdateMultiItem(rg, idx);
        } else {
            if (summaryHandlingModel()->data(rowidx.parent(), ItemTypeRole).toInt() == TypeMulti && !isExpanded) {
                // continue;
            }

            GraphicsItem *item = findItem(idx);
            if (!item) {
                item = createItem(static_cast<ItemType>(itemtype));
                item->setIndex(idx);
                insertItem(idx, item);
            }
            const Span span = rowController()->rowGeometry(sidx);
            item->updateItem(span, idx);
        }
    }
    blockSignals(blocked);
}

void GraphicsScene::insertItem(const QPersistentModelIndex &idx, GraphicsItem *item)
{
    if (!d->constraintModel.isNull()) {
        // Create items for constraints
        const QModelIndex sidx = summaryHandlingModel()->mapToSource(idx);
        const QList<Constraint> clst = d->constraintModel->constraintsForIndex(sidx);
        for (const Constraint &c : clst) {
            QModelIndex other_idx;
            if (c.startIndex() == sidx) {
                other_idx = c.endIndex();
                GraphicsItem *other_item = d->items.value(summaryHandlingModel()->mapFromSource(other_idx), 0);
                if (!other_item)
                    continue;
                auto *citem = new ConstraintGraphicsItem(c);
                item->addStartConstraint(citem);
                other_item->addEndConstraint(citem);
                addItem(citem);
            } else if (c.endIndex() == sidx) {
                other_idx = c.startIndex();
                GraphicsItem *other_item = d->items.value(summaryHandlingModel()->mapFromSource(other_idx), 0);
                if (!other_item)
                    continue;
                auto *citem = new ConstraintGraphicsItem(c);
                other_item->addStartConstraint(citem);
                item->addEndConstraint(citem);
                addItem(citem);
            } else {
                assert(0); // Impossible
            }
        }
    }
    d->items.insert(idx, item);
    addItem(item);
}

void GraphicsScene::removeItem(const QModelIndex &idx)
{
    // qDebug() << "GraphicsScene::removeItem("<<idx<<")";
    QHash<QPersistentModelIndex, GraphicsItem *>::iterator it = d->items.find(idx);
    if (it != d->items.end()) {
        GraphicsItem *item = *it;
        assert(item);
        // We have to remove the item from the list first because
        // there is a good chance there will be reentrant calls
        d->items.erase(it);
        {
            const auto startConstraints = item->startConstraints();
            const auto endConstraints = item->endConstraints();
            // Remove any constraintitems attached
            const QSet<ConstraintGraphicsItem *> clst =
#if QT_VERSION > QT_VERSION_CHECK(5, 14, 0)
                QSet<ConstraintGraphicsItem *>(startConstraints.begin(), startConstraints.end()) + QSet<ConstraintGraphicsItem *>(endConstraints.begin(), endConstraints.end());
#else
                QSet<ConstraintGraphicsItem *>::fromList(startConstraints) + QSet<ConstraintGraphicsItem *>::fromList(endConstraints);
#endif

            for (ConstraintGraphicsItem *citem : clst) {
                d->deleteConstraintItem(citem);
            }
        }
        // Get rid of the item
        delete item;
    }
}

GraphicsItem *GraphicsScene::findItem(const QModelIndex &idx) const
{
    if (!idx.isValid())
        return nullptr;
    assert(idx.model() == summaryHandlingModel());
    QHash<QPersistentModelIndex, GraphicsItem *>::const_iterator it = d->items.find(idx);
    return (it != d->items.end()) ? *it : 0;
}

GraphicsItem *GraphicsScene::findItem(const QPersistentModelIndex &idx) const
{
    if (!idx.isValid())
        return nullptr;
    assert(idx.model() == summaryHandlingModel());
    QHash<QPersistentModelIndex, GraphicsItem *>::const_iterator it = d->items.find(idx);
    return (it != d->items.end()) ? *it : 0;
}

void GraphicsScene::clearItems()
{
    QHash<QPersistentModelIndex, GraphicsItem *>::const_iterator it = d->items.constBegin();
    for (; it != d->items.constEnd(); ++it) {
        delete *it;
    }
    d->items.clear();

    // Clear constraints
    QList<QGraphicsItem *> items = d->q->items();
    qDeleteAll(items);
}

void GraphicsScene::updateItems()
{
    for (QHash<QPersistentModelIndex, GraphicsItem *>::iterator it = d->items.begin();
         it != d->items.end(); ++it) {
        GraphicsItem *const item = it.value();
        const QPersistentModelIndex &idx = it.key();
        item->updateItem(Span(item->pos().y(), item->rect().height()), idx);
    }
    invalidate(QRectF(), QGraphicsScene::BackgroundLayer);
}

void GraphicsScene::deleteSubtree(const QModelIndex &_idx)
{
    QModelIndex idx = dataIndex(_idx);
    if (!idx.model())
        return;
    const QModelIndex parent(idx.parent());
    const int colcount = idx.model()->columnCount(parent);
    {
        for (int i = 0; i < colcount; ++i) {
            removeItem(parent.model()->index(idx.row(), i, parent));
        }
    }
    const int rowcount = summaryHandlingModel()->rowCount(_idx);
    {
        for (int i = 0; i < rowcount; ++i) {
            deleteSubtree(summaryHandlingModel()->index(i, summaryHandlingModel()->columnCount(_idx) - 1, _idx));
        }
    }
}

ConstraintGraphicsItem *GraphicsScene::findConstraintItem(const Constraint &c) const
{
    return d->findConstraintItem(c);
}

void GraphicsScene::clearConstraintItems()
{
    // TODO
    // d->constraintItems.clearConstraintItems();
}

void GraphicsScene::slotConstraintAdded(const KDGantt::Constraint &c)
{
    d->createConstraintItem(c);
}

void GraphicsScene::slotConstraintRemoved(const KDGantt::Constraint &c)
{
    d->deleteConstraintItem(c);
}

void GraphicsScene::slotGridChanged()
{
    updateItems();
    update();
    Q_EMIT gridChanged();
}

void GraphicsScene::helpEvent(QGraphicsSceneHelpEvent *helpEvent)
{
#ifndef QT_NO_TOOLTIP
    QGraphicsItem *item = itemAt(helpEvent->scenePos(), QTransform());
    if (auto *gitem = qgraphicsitem_cast<GraphicsItem *>(item)) {
        QToolTip::showText(helpEvent->screenPos(), gitem->ganttToolTip());
    } else if (auto *citem = qgraphicsitem_cast<ConstraintGraphicsItem *>(item)) {
        QToolTip::showText(helpEvent->screenPos(), citem->ganttToolTip());
    } else {
        QGraphicsScene::helpEvent(helpEvent);
    }
#endif /* QT_NO_TOOLTIP */
}

void GraphicsScene::drawBackground(QPainter *painter, const QRectF &_rect)
{
    QRectF scn(sceneRect());
    QRectF rect(_rect);
    if (d->isPrinting && d->drawColumnLabels) {
        QRectF headerRect(scn.topLeft() + QPointF(d->labelsWidth, 0),
                          QSizeF(scn.width() - d->labelsWidth, d->rowController->headerHeight()));

        d->grid->paintHeader(painter, headerRect, rect, 0, nullptr);

#if 0
        /* We have to blank out the part of the header that is invisible during
        * normal rendering when we are printing.
        */
        QRectF labelsTabRect( scn.topLeft(), QSizeF( d->labelsWidth, headerRect.height() ) );

        QStyleOptionHeader opt;
        opt.rect = labelsTabRect.toRect();
        opt.text = QLatin1String("");
        opt.textAlignment = Qt::AlignCenter;
        style()->drawControl(QStyle::CE_Header, &opt, painter, 0);
#endif

        scn.setTop(headerRect.bottom());
        scn.setLeft(headerRect.left());
        rect = rect.intersected(scn);
    }
    d->grid->paintGrid(painter, scn, rect, d->rowController);

    d->grid->drawBackground(painter, rect);
}

void GraphicsScene::drawForeground(QPainter *painter, const QRectF &rect)
{
    d->grid->drawForeground(painter, rect);
}

void GraphicsScene::itemEntered(const QModelIndex &idx)
{
    Q_EMIT entered(idx);
}

void GraphicsScene::itemPressed(const QModelIndex &idx)
{
    Q_EMIT pressed(idx);
}

void GraphicsScene::itemClicked(const QModelIndex &idx)
{
    Q_EMIT clicked(idx);
}

void GraphicsScene::itemDoubleClicked(const QModelIndex &idx)
{
    Q_EMIT qrealClicked(idx);
}

void GraphicsScene::setDragSource(GraphicsItem *item)
{
    d->dragSource = item;
}

GraphicsItem *GraphicsScene::dragSource() const
{
    return d->dragSource;
}

/*! Print the Gantt chart using \a printer. If \a drawRowLabels
 * is true (the default), each row will have it's label printed
 * on the left side. If \a drawColumnLabels is true (the
 * default), each column will have it's label printed at the
 * top side.
 *
 * This version of print() will print multiple pages.
 */
void GraphicsScene::print(QPrinter *printer, bool drawRowLabels, bool drawColumnLabels)
{
#ifndef HAVE_PRINTER
    Q_UNUSED(printer);
    Q_UNUSED(drawRowLabels);
    Q_UNUSED(drawColumnLabels);
#else
    QPainter painter(printer);
    doPrint(&painter, printer->pageLayout().paintRectPixels(printer->resolution()), sceneRect().left(), sceneRect().right(), printer, drawRowLabels, drawColumnLabels);
#endif
}

/*! Print part of the Gantt chart from \a start to \a end using \a printer.
 * If \a drawRowLabels is true (the default), each row will have it's
 * label printed on the left side. If \a drawColumnLabels is true (the
 * default), each column will have it's label printed at the
 * top side.
 *
 * This version of print() will print multiple pages.
 *
 * To print a certain range of a chart with a DateTimeGrid, use
 * qreal DateTimeGrid::mapFromDateTime( const QDateTime& dt) const
 * to figure out the values for \a start and \a end.
 */
void GraphicsScene::print(QPrinter *printer, qreal start, qreal end, bool drawRowLabels, bool drawColumnLabels)
{
#ifndef HAVE_PRINTER
    Q_UNUSED(printer);
    Q_UNUSED(start);
    Q_UNUSED(end);
    Q_UNUSED(drawRowLabels);
    Q_UNUSED(drawColumnLabels);
#else
    QPainter painter(printer);
    doPrint(&painter, printer->pageLayout().paintRectPixels(printer->resolution()), start, end, printer, drawRowLabels, drawColumnLabels);
#endif
}

/*! Render the GanttView inside the rectangle \a target using the painter \a painter.
 * If \a drawRowLabels is true (the default), each row will have it's
 * label printed on the left side. If \a drawColumnLabels is true (the
 * default), each column will have it's label printed at the
 * top side.
 */
void GraphicsScene::print(QPainter *painter, const QRectF &_targetRect, bool drawRowLabels, bool drawColumnLabels)
{
    QRectF targetRect(_targetRect);
    if (targetRect.isNull()) {
        targetRect = sceneRect();
    }

    doPrint(painter, targetRect, sceneRect().left(), sceneRect().right(), nullptr, drawRowLabels, drawColumnLabels);
}

/*! Render the GanttView inside the rectangle \a target using the painter \a painter.
 * If \a drawRowLabels is true (the default), each row will have it's
 * label printed on the left side. If \a drawColumnLabels is true (the
 * default), each column will have it's label printed at the
 * top side.
 *
 * To print a certain range of a chart with a DateTimeGrid, use
 * qreal DateTimeGrid::mapFromDateTime( const QDateTime& dt) const
 * to figure out the values for \a start and \a end.
 */
void GraphicsScene::print(QPainter *painter, qreal start, qreal end,
                          const QRectF &_targetRect, bool drawRowLabels, bool drawColumnLabels)
{
    QRectF targetRect(_targetRect);
    if (targetRect.isNull()) {
        targetRect = sceneRect();
    }

    doPrint(painter, targetRect, start, end, nullptr, drawRowLabels, drawColumnLabels);
}

/*!\internal
 */
void GraphicsScene::doPrint(QPainter *painter, const QRectF &targetRect,
                            qreal start, qreal end,
                            QPrinter *printer, bool drawRowLabels, bool drawColumnLabels)
{
    assert(painter);
    d->isPrinting = true;
    d->drawColumnLabels = drawColumnLabels;
    d->labelsWidth = 0.0;
    QFont sceneFont(font());
#ifdef HAVE_PRINTER
    if (printer) {
        sceneFont = QFont(font(), printer);
        if (font().pointSizeF() >= 0.0)
            sceneFont.setPointSizeF(font().pointSizeF());
        else if (font().pointSize() >= 0)
            sceneFont.setPointSize(font().pointSize());
        else
            sceneFont.setPixelSize(font().pixelSize());
    }
#endif

    QGraphicsTextItem dummyTextItem(QLatin1String("X"));
    dummyTextItem.adjustSize();
    QFontMetrics fm(dummyTextItem.font());
    sceneFont.setPixelSize(fm.height());

    const QRectF oldScnRect(sceneRect());
    QRectF scnRect(oldScnRect);
    scnRect.setLeft(start);
    scnRect.setRight(end);
    bool b = blockSignals(true);

    /* column labels */
    if (d->drawColumnLabels) {
        QRectF headerRect(scnRect);
        headerRect.setHeight(-d->rowController->headerHeight());
        scnRect.setTop(scnRect.top() - d->rowController->headerHeight());
    }

    /* row labels */
    QVector<QGraphicsTextItem *> textLabels;
    if (drawRowLabels) {
        qreal textWidth = 0.;
        QModelIndex sidx = summaryHandlingModel()->mapToSource(summaryHandlingModel()->index(0, 0, rootIndex()));
        do {
            QModelIndex idx = summaryHandlingModel()->mapFromSource(sidx);
            const Span rg = rowController()->rowGeometry(sidx);
            const QString txt = idx.data(Qt::DisplayRole).toString();
            auto *item = new QGraphicsTextItem(txt);
            addItem(item);
            textLabels << item;
            item->adjustSize();
            textWidth = qMax(item->textWidth(), textWidth);
            item->setPos(0, rg.start());
        } while ((sidx = rowController()->indexBelow(sidx)).isValid());
        // Add a little margin to textWidth
        textWidth += QFontMetricsF(sceneFont).horizontalAdvance(QString::fromLatin1("X"));
        for (QGraphicsTextItem *item : std::as_const(textLabels)) {
            item->setPos(scnRect.left() - textWidth, item->y());
            item->show();
        }
        scnRect.setLeft(scnRect.left() - textWidth);
        d->labelsWidth = textWidth;
    }

    setSceneRect(scnRect);

    painter->save();
    painter->setClipRect(targetRect);

    qreal yratio = targetRect.height() / scnRect.height();
    /* If we're not printing multiple pages,
     * check if the span fits and adjust:
     */
    if (!printer && targetRect.width() / scnRect.width() < yratio) {
        yratio = targetRect.width() / scnRect.width();
    }

    qreal offset = scnRect.left();
    int pagecount = 0;
    while (offset < scnRect.right()) {
        painter->setFont(sceneFont);
        render(painter, targetRect, QRectF(QPointF(offset, scnRect.top()), QSizeF(targetRect.width() / yratio, scnRect.height())));
        offset += targetRect.width() / yratio;
        ++pagecount;
        if (printer && offset < scnRect.right()) {
#ifdef HAVE_PRINTER
            printer->newPage();
#endif
        } else {
            break;
        }
    }

    d->isPrinting = false;
    d->drawColumnLabels = true;
    d->labelsWidth = 0.0;
    qDeleteAll(textLabels);
    blockSignals(b);
    setSceneRect(oldScnRect);
    painter->restore();
}

#include "moc_kdganttgraphicsscene.cpp"

#ifndef KDAB_NO_UNIT_TESTS
#include "unittest/test.h"

#include <QGraphicsLineItem>
#include <QPointer>
#include <QStandardItemModel>

#include "kdganttgraphicsview.h"

class SceneTestRowController : public KDGantt::AbstractRowController
{
private:
    static const int ROW_HEIGHT;
    QPointer<QAbstractItemModel> m_model;

public:
    SceneTestRowController()
    {
    }

    void setModel(QAbstractItemModel *model)
    {
        m_model = model;
    }

    /*reimp*/ int headerHeight() const override
    {
        return 40;
    }

    /*reimp*/ bool isRowVisible(const QModelIndex &) const override
    {
        return true;
    }
    /*reimp*/ bool isRowExpanded(const QModelIndex &) const override
    {
        return false;
    }
    /*reimp*/ KDGantt::Span rowGeometry(const QModelIndex &idx) const override
    {
        return KDGantt::Span(idx.row() * ROW_HEIGHT, ROW_HEIGHT);
    }
    /*reimp*/ int maximumItemHeight() const override
    {
        return ROW_HEIGHT / 2;
    }
    /*reimp*/ int totalHeight() const override
    {
        return m_model->rowCount() * ROW_HEIGHT;
    }

    /*reimp*/ QModelIndex indexAt(int height) const override
    {
        return m_model->index(height / ROW_HEIGHT, 0);
    }

    /*reimp*/ QModelIndex indexBelow(const QModelIndex &idx) const override
    {
        if (!idx.isValid())
            return QModelIndex();
        return idx.model()->index(idx.row() + 1, idx.column(), idx.parent());
    }
    /*reimp*/ QModelIndex indexAbove(const QModelIndex &idx) const override
    {
        if (!idx.isValid())
            return QModelIndex();
        return idx.model()->index(idx.row() - 1, idx.column(), idx.parent());
    }
};

class TestLineItem : public QGraphicsLineItem
{
public:
    TestLineItem(bool *destroyedFlag)
        : QGraphicsLineItem(0, 0, 10, 10)
        , // geometry doesn't matter
        m_destroyedFlag(destroyedFlag)
    {
    }

    ~TestLineItem() override
    {
        *m_destroyedFlag = true;
    }

private:
    bool *m_destroyedFlag;
};

const int SceneTestRowController::ROW_HEIGHT = 30;

KDAB_SCOPED_UNITTEST_SIMPLE(KDGantt, GraphicsView, "test")
{
    QStandardItemModel model;

    auto *item = new QStandardItem();
    item->setData(KDGantt::TypeTask, KDGantt::ItemTypeRole);
    item->setData(QString::fromLatin1("Decide on new product"));
    item->setData(QDate(2007, 3, 1).startOfDay(), KDGantt::StartTimeRole);
    item->setData(QDate(2007, 3, 3).startOfDay(), KDGantt::EndTimeRole);

    auto *item2 = new QStandardItem();
    item2->setData(KDGantt::TypeTask, KDGantt::ItemTypeRole);
    item2->setData(QString::fromLatin1("Educate personnel"));
    item2->setData(QDate(2007, 3, 3).startOfDay(), KDGantt::StartTimeRole);
    item2->setData(QDate(2007, 3, 6).startOfDay(), KDGantt::EndTimeRole);

    model.appendRow(item);
    model.appendRow(item2);

    SceneTestRowController rowController;
    rowController.setModel(&model);

    KDGantt::GraphicsView graphicsView;
    graphicsView.setRowController(&rowController);
    graphicsView.setModel(&model);

    // Now the interesting stuff - the items above are just for a "realistic environment"

    bool foreignItemDestroyed = false;
    auto *foreignItem = new TestLineItem(&foreignItemDestroyed);
    graphicsView.scene()->addItem(foreignItem);

    assertFalse(foreignItemDestroyed);
    graphicsView.updateScene();
    assertFalse(foreignItemDestroyed);
}
#endif /* KDAB_NO_UNIT_TESTS */
